The first picture is of a bee home we don't recommend - it was something donated to us and it has
bees in it...so we've kept it around.
The second bee home, with the wire over it, has nesting trays, which fit together to create nesting holes. The trays are super easy to take apart and clean out, which can be an important step in interrupting fungi and pests that attack the bee larva.
Here is a
post from Robbie, where they did just that, took the trays apart and cleaned them out. Robbie wrote:
After lunch Fred wanted to get us out of the heat so we cleaned up a leafcutter bee box for their new season to pollinate. We removed the cocoons from the tubes and checked for parasites. Once they were cleared, we cleaned the frames with a wire brush and put the box back together. The cocoons were put in a mesh bag above the tubes for the larvae to hatch and repeat their cycle.
Robbie's first picture above shows cleaning the trays. (I'm not sure if that dark colored critter is a dried out leafcutter larva or not - I think they are usually a milky white color.) Though he said that the larva in the second picture above was a parasite that invaded the cocoons.
Our bee house and trays for the leafcutter solitary bees were a
gift from
Crown Bees. Certainly a world-wide expert on solitary bees and their amazing pollinating power. See also
Crown Bees' Native Bee Guide (in the permies digital market).